The present invention relates to a storage apparatus for optically recording and reproducing information to/from an interchangeable medium such as an MO cartridge or the like and, more particularly, to a storage apparatus in which a battery pack and an interface card for an upper apparatus are combined in addition to an apparatus main body and which is suitable to carry.
Attention is paid to an optical disk as a storage medium as a center of multi-media which is rapidly developing in recent years. For example, as for an MO cartridge of 3.5 inches, MO cartridges of 128 MB, 230 MB, and the like are provided. An optical disk drive using such an MO cartridge is provided as an external storage apparatus of a desk-top type personal computer. Further, it is strongly desired to use the optical disk drive in a notebook-sized personal computer having an excellent portability which is rapidly spread in recent years.
A conventional optical disk drive, however, is mainly used on the assumption that it is fixedly connected to the desk-top type computer as a prerequisite. When the optical disk drive is used as an external storage of the notebook-sized computer, there are various problems with respect to portability. For example, when the optical disk drive is used in the notebook-sized personal computer, accessories such as battery unit, interface unit, various connecting cables, and the like have to be also carried in addition to the optical disk drive. If the user forgets to carry any one of the accessories, the optical disk drive cannot be used. When the optical disk drive is carried with the accessories in addition to the notebook-sized personal computer, since the accessories are separate, it is inconvenient to enclose and take out the accessories into/from a bag or the like and it is difficult to use them. Further, since a medium insertion port of the optical disk drive is exposed on the front surface of a casing, when the optical disk drive is put as it is in the bag and is carried, there is a fear such that a foreign material enters from the medium insertion port during the carrying and when the optical disk drive is operated in such a state, the medium or drive is damaged.
When the optical disk drive is used as an external storage of the notebook-sized personal computer, the optical disk drive uses, for example, an ATA interface (AT attachment interface) and the notebook-sized personal computer uses a PCMCIA interface according to the PCMCIA (Personal Computer Memory Card International Association). Therefore, a converting circuit to obtain a compatibility between the ATA interface and the PCMCIA interface is necessary. When the interface converting circuit is provided in the optical disk drive or the notebook-sized personal computer, since it cannot be adapted to other interfaces, it lacks generality and the apparatus is complicated. The notebook-sized personal computer usually has a card slot for enabling a device to be connected from the outside by using a PC card. It is, therefore, desirable to provide the interface converting circuit which obtains a compatibility with the optical disk drive as a PC card. A card having a converting function between the ATA interface on the device side and the PCMCIA interface on the host side is called a PCMCIA card hereinbelow. In case of connecting the optical disk drive as a device side to the notebook-sized personal computer as a host side by using and inserting the PCMCIA card into the card slot of the notebook-sized personal computer, when a power source is supplied from the outside to only the device side, a current flows to the host side whose operation is stopped depending on a power source sequence, so that the current is unnecessarily consumed. When the power source is supplied from the outside to only the host side, a current flows to the device side whose operation is stopped and the current on the host side is also unnecessarily consumed similarly. Since the notebook-sized personal computer and the optical disk drive which is used as an external storage of the computer are made operative by the power source supplied from a battery unit, there is an inconvenience such that such a current consumption shortens a usable time by the battery.
Further, when the optical disk drive is used as an external storage of the notebook-sized personal computer by the power supply by the battery unit, a low battery voltage is detected and an abnormality is notified by a buzzer or a light-on of an LED since data is lost or the medium is damaged when the battery voltage on the device side is extinguished. There is, however, a case where the battery voltage is extinguished without being aware of the buzzer or LED light-on by the user, so that the battery is finished and the data or medium is damaged. There is also a case where even if the user is aware of the low battery voltage, the apparatus doesn't immediately enter the unusable state, he continues to use the computer, and after all, the battery voltage is extinguished and the data or medium is damaged.